Robert s



UNITED STATES PATENT OFFICE,

ROBERT S. MILLER, OF VVIL MINGTON, DELAWUARE, ASSIGNOR OF ONE-HALF TO JAMES VVILBUR CARRIER, OF SAME PLACE.

BOILER AND PIPE COVERING.

SPECIFICATION forming part of Letters Patent No. 465,718, dated December 22, 1891.

Application filed August 5, 1891. $erial No. 401,773. (Specimens) To all whom it may concern.-

Be it known that I, ROBERT S. MILLER, residing at \Vilmington, New Castle county, State of Delaware, have invented a new and useful Improvement in Boiler and Pipe Coverings, of which the following is a specification.

My invention consists in an improved composition to form an elastic boiler and steamto pipe covering.

The following are the ingredients for making five barrels of the covering: refined or washed kaolin, one and one-half barrels; cow or goat hair, one-half bushel; asbestus fiber,

two bushels; feldspar, three peeks; plasterof-paris, twelve quarts; rag pulp, one barrel; ground cork, ten pounds; sal-ammoniac, one pound. Add sufficient water to make a mortar and mix thoroughly.

The composition is put on in two coats. For the first coat for boiler and steam-pipe covering the plaster-of-paris is omitted, and the amount of asbestos is increased and of rag pulp diminished, depending on the amount 2 5 of heat. Whenthe composition is tobespread 011 canvas for covering pipes, the kaolin is reduced one-half for both first and second coatings. Ordinarily, however, the composition is used as per formula given, and is applied 0 with a trowel like plaster, the boiler or pipe being first covered with wire-netting, into which the composition penetrates and by which it is. retained in a manner similar to that by which laths holds the plaster.

The kaolin, hair, and asbestos are common ingredients in boiler-coverings, and for these no special claims are made.

The following are the distinctive features of my invention: The use of sal-ammoniac o neutralizes grease or oil and makes the covering adhere to greasy iron. It also destroys all bad odor arising from the covering coming in contact with fire or steam heated surfaces. The feldspar gives the composition a stiflf and sticky nature and causes the covering to adhere to the iron without the use of straps. It is also one of the ingredients that help to make the covering elastic. ter-of-paris is not put in as a cement, as the cov- 5o erin g will hold together without it, and an ex- The plascess of plaster-of-paris would make the covering so hard that it would crack with the expansion and contraction of the boiler. Either plaster-of-paris or kaolin when used alone as an outside coating or finish for boiler and steam pipe coverings will crack; but when the plaster-of-paris,feldspar, and kaolin are thoroughly mixed together and mixed with the other ingredients of the covering they give the covering a smooth and water-proof 6o finish, which will take a high polish by rubbing with a cloth, and also make the covering elastic so that it will expand and contract with theiron without cracking. This smooth glossy water-proof finish prevents cracks and constitutes one of the principal advantages of this covering.

The following are some of the advantages claimed for the composition taken as a whole:

First, it is fire-proof, (cannot be made to burn.)

Second, being elastic and expanding and contracting with the boiler, it is free from cracks.

Third, it never falls off and clings to all work without straps, and not being made of perishable materials is claimed to be the most durableof coverings.

Fourth, it is an anti-rust covering, containing no ingredients that will corrode the iron and prevents the formation of rust.

Fifth, it is an odorless covering, which is a great advantage in a dwelling-house.

Sixth, it is water-proof.

Seventh, it is one of the best non-conduct ors of heat.

Eighth, the composition takes a high polish and presents a beautiful appearance.

Hydraulic cement or lime may be used as a substitute for the plaster-of-paris, and in this case would be the equivalent thereof; but the cement or lime must not be used in excess, as then the covering would not be elastic.

Cements have been used in boiler-coverings before; but they were used for an entirely 5 different purposenamely, to hold the covering together, and such coverings crack.

This water-proof finish on my covering saves the expense of putting on canvas or other similar outside coverings, which are not wa- 10o of-paris or its described equivalent, rag pulp, ground cork, and sal-animoniao in or about the proportions described.

' ROBERT S. MILLER.

I Witnesses:

J. W. CARRIER, JVIARGARET MILLER. 

